[dxf] Address review: prefer overridden layer name over layer title (…

…the former can be changed in the export dialog, whereas the latter must be done in the layer properties, therefore, overridden layer name is closer to the export intention and should take the precedence)

src/analysis/processing/qgsalgorithmdxfexport.cpp

@@ -48,7 +48,7 @@ QString QgsDxfExportAlgorithm::groupId() const
 QString QgsDxfExportAlgorithm::shortHelpString() const
 {
   return QObject::tr( "Exports layers to DXF file. For each layer, you can choose a field whose values are used to split features in generated destination layers in the DXF output.\n\n"
-                      "If no field is chosen, you can still override the output layer name by preferring layer title (set in layer properties) or by directly entering a new output layer name in the Configure Layer panel." );
+                      "If no field is chosen, you can still override the output layer name by directly entering a new output layer name in the Configure Layer panel or by preferring layer title (set in layer properties) to layer name." );
 }
 
 QgsDxfExportAlgorithm *QgsDxfExportAlgorithm::createInstance() const
@@ -72,7 +72,7 @@ void QgsDxfExportAlgorithm::initAlgorithm( const QVariantMap & )
   addParameter( extentParam.release() );
   addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "SELECTED_FEATURES_ONLY" ), QObject::tr( "Use only selected features" ), false ) );
   std::unique_ptr<QgsProcessingParameterBoolean> useTitleParam = std::make_unique<QgsProcessingParameterBoolean>( QStringLiteral( "USE_LAYER_TITLE" ), QObject::tr( "Use layer title as name" ), false );
-  useTitleParam->setHelp( QObject::tr( "If no attribute is chosen, prefer layer title (set in layer properties) to layer name" ) );
+  useTitleParam->setHelp( QObject::tr( "If no attribute is chosen and layer name is not being overridden, prefer layer title (set in layer properties) to layer name" ) );
   addParameter( useTitleParam.release() );
   addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "FORCE_2D" ), QObject::tr( "Force 2D output" ),  false ) );
   addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "MTEXT" ), QObject::tr( "Export labels as MTEXT elements" ),  true ) );

src/core/dxf/qgsdxfexport.cpp

@@ -2391,10 +2391,18 @@ QStringList QgsDxfExport::encodings()
 QString QgsDxfExport::layerName( QgsVectorLayer *vl ) const
 {
   Q_ASSERT( vl );
-  if ( mLayerTitleAsName && ( !vl->metadata().title().isEmpty() || !vl->serverProperties()->title().isEmpty() ) )
+  if ( !mLayerOverriddenName.value( vl->id(), QString() ).isEmpty() )
+  {
+    return mLayerOverriddenName.value( vl->id() );
+  }
+  else if ( mLayerTitleAsName && ( !vl->metadata().title().isEmpty() || !vl->serverProperties()->title().isEmpty() ) )
+  {
     return !vl->metadata().title().isEmpty() ? vl->metadata().title() : vl->serverProperties()->title();
+  }
   else
-    return mLayerOverriddenName.value( vl->id(), vl->name() );
+  {
+    return vl->name();
+  }
 }
 
 void QgsDxfExport::drawLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings )

src/core/dxf/qgsdxfexport_p.h

@@ -105,7 +105,7 @@ struct DxfLayerJob
     QgsLabelSinkProvider *labelProvider = nullptr;
     QgsRuleBasedLabelSinkProvider *ruleBasedLabelProvider = nullptr;
     QString splitLayerAttribute;
-    QString layerDerivedName;  // Obtained from layer title, name or overridden name
+    QString layerDerivedName;  // Obtained from overridden name, title or layer name
     QSet<QString> attributes;
 
   private:

src/ui/qgsdxfexportdialogbase.ui

@@ -172,7 +172,7 @@
      <item row="0" column="0">
       <widget class="QCheckBox" name="mLayerTitleAsName">
        <property name="toolTip">
-        <string>If no attribute is chosen, prefer layer title (set in layer properties) to layer name.</string>
+        <string>If no attribute is chosen and layer name is not being overridden, prefer layer title (set in layer properties) to layer name.</string>
        </property>
        <property name="text">
         <string>Use layer title as name if set</string>

tests/src/core/testqgsdxfexport.cpp

@@ -1813,8 +1813,8 @@ void TestQgsDxfExport::testOutputLayerNamePrecedence()
 {
   // Test that output layer name precedence is:
   // 1) Attribute (if any)
-  // 2) Layer title (if any)
-  // 3) Overridden name (if any)
+  // 2) Overridden name (if any)
+  // 3) Layer title (if any)
   // 4) Layer name
 
   const QString layerTitle = QStringLiteral( "Point Layer Title" );
@@ -1871,8 +1871,8 @@ void TestQgsDxfExport::testOutputLayerNamePrecedence()
   dxfFile2.close();
 
   QVERIFY( !fileContainsText( file2, QStringLiteral( "nan.0" ) ) );
-  QVERIFY( fileContainsText( file2, layerTitle ) );
-  QVERIFY( !fileContainsText( file2, layerOverriddenName ) );
+  QVERIFY( !fileContainsText( file2, layerTitle ) );
+  QVERIFY( fileContainsText( file2, layerOverriddenName ) );
   QVERIFY( !fileContainsText( file2, mPointLayer->name() ) );
 
   // reload and compare
@@ -1882,20 +1882,20 @@ void TestQgsDxfExport::testOutputLayerNamePrecedence()
   QCOMPARE( result->wkbType(), Qgis::WkbType::Point );
   QgsFeature feature;
   result->getFeatures().nextFeature( feature );
-  QCOMPARE( feature.attribute( "Layer" ), layerTitle );
+  QCOMPARE( feature.attribute( "Layer" ), layerOverriddenName );
   QCOMPARE( result->uniqueValues( 0 ).count(), 1 ); // "Layer" field
 
-  // C) No attribute given, choose no title
-  d.setLayerTitleAsName( false );
+  // C) No attribute given, no override
+  d.addLayers( QList< QgsDxfExport::DxfLayer >() << QgsDxfExport::DxfLayer( mPointLayer, -1, false, -1 ) ); // this replaces layers
 
-  const QString file3 = getTempFileName( "name_precedence_c_no_attr_no_title_dxf" );
+  const QString file3 = getTempFileName( "name_precedence_c_no_attr_no_override_dxf" );
   QFile dxfFile3( file3 );
   QCOMPARE( d.writeToFile( &dxfFile3, QStringLiteral( "CP1252" ) ), QgsDxfExport::ExportResult::Success );
   dxfFile3.close();
 
   QVERIFY( !fileContainsText( file3, QStringLiteral( "nan.0" ) ) );
-  QVERIFY( !fileContainsText( file3, layerTitle ) );
-  QVERIFY( fileContainsText( file3, layerOverriddenName ) );
+  QVERIFY( fileContainsText( file3, layerTitle ) );
+  QVERIFY( !fileContainsText( file3, layerOverriddenName ) );
   QVERIFY( !fileContainsText( file3, mPointLayer->name() ) );
 
   // reload and compare
@@ -1904,11 +1904,12 @@ void TestQgsDxfExport::testOutputLayerNamePrecedence()
   QCOMPARE( result->featureCount(), mPointLayer->featureCount() );
   QCOMPARE( result->wkbType(), Qgis::WkbType::Point );
   result->getFeatures().nextFeature( feature );
-  QCOMPARE( feature.attribute( "Layer" ), layerOverriddenName );
+  QCOMPARE( feature.attribute( "Layer" ), layerTitle );
   QCOMPARE( result->uniqueValues( 0 ).count(), 1 ); // "Layer" field
 
   // D) No name options given, use default layer name
   d.addLayers( QList< QgsDxfExport::DxfLayer >() << QgsDxfExport::DxfLayer( mPointLayer ) ); // This replaces layers
+  d.setLayerTitleAsName( false );
 
   const QString file4 = getTempFileName( "name_precedence_d_no_anything_dxf" );
   QFile dxfFile4( file4 );